w3m: Fix ubilding with unified headers

packages/w3m/Str.h.patch

@@ -0,0 +1,11 @@
+diff -u -r ../w3m-0.5.3-git20170102/Str.h ./Str.h
+--- ../w3m-0.5.3-git20170102/Str.h	2017-01-02 13:43:38.000000000 +0100
++++ ./Str.h	2017-06-29 01:05:35.903835683 +0200
+@@ -17,6 +17,7 @@
+ #define GC_STR_H
+ #include <stdio.h>
+ #include <string.h>
++#include <strings.h>
+ #ifdef __EMX__
+ #define strcasecmp	stricmp
+ #define strncasecmp	strnicmp